3. The instructions to the American Peace Commissioner adopted on 14 Aug. provided as one of the ultimata that the western boundary of the United States would be the Mississippi River, thus taking in the vast claims by Virginia and other states. Such an ultimatum had also appeared in the draft committee report of 23 Feb. on the objects to be pursued in any peace negotiations. There an additional ultimatum had provided “that free commerce be allowed to the subjects of the United States with some port or ports below the southern boundary of the said states.” The draft document also provided that if Britain ceded Florida to the United States it could be receded to Spain “for an adequate compensation” (
, 14:956–960; 13:239–244).
The instructions of 14 Aug. mentioned neither a port on the Mississippi nor the ultimate disposition of Florida. Instead, those questions were dealt with in instructions to the American minister charged with negotiating a treaty with Spain, which were being considered when Lovell wrote. Adopted on 29 Sept., the instructions provided that Spain, should it accede to the Franco-American alliance, would not be precluded from obtaining Florida and, indeed, that if Florida were conquered, the United States would guarantee Spain's possession, “provided always, that the United States shall enjoy the free navigation of the River Mississippi into and from the sea.” In addition, the minister was directed to “endeavour to obtain some convenient port or ports” on the Mississippi below the southern border: the 31st parallel (same, 15:1118–1120). Lovell, however, still thought that acquiring port rights should be an ultimatum in a Spanish treaty. Without a port or ports to which the produce of the western lands could be taken for shipment and through which they could be supplied, the acquisition of those lands in a peace treaty was of doubtful value.
The instructions of 29 Sept., intended to allay Spanish fears regarding American intentions toward Spanish possessions in North America, came to nothing. The United States, in Art. 8 of the peace treaty of 1783, gained the same right that Britain had acquired in Art. 7 of the definitive Anglo-French peace treaty ending the Seven Years' War: to navigate the Mississippi from its source to the sea. But Spain's acquisition of the Floridas in 1783 gave it control of both banks of the Mississippi below the 31st parallel, and thus a strong legal position for denying free passage to the sea. Not until Pinckney's treaty of 1795 did Spain agree to permit American vessels to navigate the Mississippi through its territory and make the concession meaningful by allowing American citizens to land goods at New Orleans or some other place within its territory (Miller, ed., Treaties
, 2:155, 321–322, 337; Samuel Flagg Bemis, Pinckney's Treaty
, Baltimore, 1926, p. 1–4, 42, 51–55)